MAGNETIC SENSOR

Abstract

A magnetic sensor comprises at least one MR element, a ferromagnetic layer deposited to overlap the at least one MR element when viewed in a first direction, an insulator layer deposited on two sides of the at least one MR element in a second direction, and an antiferromagnetic layer deposited on the at least one MR element, the ferromagnetic layer, and the insulator layer. The antiferromagnetic layer has an antiferromagnetic portion facing the ferromagnetic layer and a non-facing portion facing the at least one MR element and the insulator layer, but not the ferromagnetic layer. There is no magnetic layer between the at least one MR element and the antiferromagnetic layer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The present invention relates to a magnetic sensor configured to be capable of applying a bias magnetic field to a magnetoresistive element. 2. Description of the invention

[0002] Magnetic sensors are used for a wide variety of applications. Examples of known magnetic sensors include a magnetoresistive spin-valve element provided on a substrate. The magnetoresistive spin-valve element comprises a magnetization-fixed layer whose magnetization is fixed in a specific direction, a free layer with a magnetization whose direction is variable depending on the direction of a target magnetic field, and a gap layer deposited between the magnetization-fixed layer and the free layer.

[0003] Some magnetic sensors incorporate means for applying a bias magnetic field to the magnetoresistive element. The bias magnetic field is used, for example, to enable the magnetoresistive element to respond linearly to a change in the strength of the target magnetic field. In a magnetic sensor using a spin-valve magnetoresistive element, the bias magnetic field is also used to cause the free layer to have a single magnetic domain and to orient the magnetization of the free layer in a specific direction when no target magnetic field is present.

[0004] As a means for generating a bias magnetic field, a magnetic field generator formed by stacking an antiferromagnetic layer and a ferromagnetic layer is known. Japanese Published Patent Application No. 2015-125020 and Japanese Published Patent Application No. 2016-176911 disclose a magnetic sensor comprising a magnetoresistive element and two magnetic field generators deposited with the magnetoresistive element between them.

[0005] To increase the strength of the bias magnetic field applied to the magnetoresistive element, it is desirable to reduce the distance between the magnetoresistive element and the magnetic field generator and increase the size of the magnetic field generator. One way to increase the strength of the bias magnetic field applied to the magnetoresistive element is, for example, to form an insulator layer around the entire magnetoresistive element and then form a magnetic field generator on top of the magnetoresistive element and the insulator layer, covering the entire magnetoresistive element. However, this would cause the magnetic layer contained in the magnetic field generator to act as a shield, resulting in a reduction in the sensitivity of the magnetoresistive element. SUMMARY OF THE INVENTION

[0006] It is an object of the present invention to provide a magnetic sensor capable of preventing a reduction in sensitivity of a magnetoresistive element.

[0007] A magnetic sensor according to the present invention comprises: at least one magnetoresistive element comprising a plurality of magnetic films stacked on one another; a first ferromagnetic layer made of a ferromagnetic material, the first ferromagnetic layer being deposited so as to overlap the at least one magnetoresistive element when viewed in a first direction orthogonal to a stacking direction of the plurality of magnetic films; an insulator layer made of an insulating material, the insulator layer being deposited on two sides of the at least one magnetoresistive element in a second direction orthogonal to each of the stacking direction and the first direction; and an antiferromagnetic layer deposited on the at least one magnetoresistive element, the first ferromagnetic layer, and the insulator layer.The antiferromagnetic layer has a first antiferromagnetic portion facing the first ferromagnetic layer and a non-facing portion facing the at least one magnetoresistive element and the insulator layer, but not facing the first ferromagnetic layer. There is no magnetic layer between the at least one magnetoresistive element and the antiferromagnetic layer.

[0008] In the magnetic sensor of the present invention, the antiferromagnetic layer is deposited on the at least one magnetoresistive element, the first ferromagnetic layer, and the insulator layer. The antiferromagnetic layer has a first antiferromagnetic portion facing the first ferromagnetic layer and a non-facing portion facing the at least one magnetoresistive element and the insulator layer, but not the first ferromagnetic layer. There is no magnetic layer between the at least one magnetoresistive element and the antiferromagnetic layer. According to the present invention, a reduction in the sensitivity of the magnetoresistive element can therefore be prevented.

[0009] Other and further objects, features and advantages of the present invention will be set forth in more detail in the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings are included to facilitate understanding of the disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of the technology. Fig. 1 is a perspective view showing a magnetic sensor device including a magnetic sensor according to a first embodiment of the present invention. Fig. 2 is a functional block diagram showing a configuration of the magnetic sensor device in the first embodiment of the present invention. Fig. 3 is a circuit diagram showing a circuit configuration of the magnetic sensor according to the first embodiment of the present invention. Fig. 4 is a perspective view showing a part of a first detection circuit in the first embodiment of the present invention. Fig. 5 is a plan view showing a part of the first detection circuit in the first embodiment of the present invention. Fig. 6 is a plan view showing a part of a second detection circuit in the first embodiment of the present invention. Fig. 7 is a plan view showing a main part of the magnetic sensor according to the first embodiment of the present invention. Fig. 8 is a plan view of a magnetoresistive element, a magnetic field generator, and an insulator layer in the first embodiment of the present invention. Fig. 9 is a sectional view showing a part of a section at a position shown in Fig. 7 is marked by the line 9-9-. Fig. 10 is a sectional view showing a part of a section at a position shown in Fig. 7 is marked by the line 10-10-. Fig. 11 is a sectional view showing a method of manufacturing a magnetic field generator of a comparative example. Fig. 12A and Fig. 12B are each a sectional view showing a method of forming the magnetic field generator in the first embodiment of the present invention. Fig. 13 is a plan view showing a main part of a first modification example of the magnetic sensor according to the first embodiment of the present invention. Fig. 14 is a plan view showing a main part of a second modification example of the magnetic sensor according to the first embodiment of the present invention. Fig. 15 is a plan view showing a main part of a third modification example of the magnetic sensor according to the first embodiment of the present invention. Fig. 16 is a sectional view showing a main part of a fourth modification example of the magnetic sensor according to the first embodiment of the present invention. Fig. 17 is a sectional view showing a main part of a fifth modification example of the magnetic sensor according to the first embodiment of the present invention. Fig. 18 is a sectional view showing a main part of a sixth modification example of the magnetic sensor according to the first embodiment of the present invention. Fig. 19 is a sectional view showing a main part of a seventh modification example of the magnetic sensor according to the first embodiment of the present invention. Fig. 20 is a perspective view showing a magnetic sensor system including a magnetic sensor according to a second embodiment of the present invention. Fig. 21 is a circuit diagram showing a circuit configuration of the magnetic sensor according to the second embodiment of the present invention. Fig. 22 is a perspective view showing a part of the magnetic sensor according to the second embodiment of the present invention. Fig. 23 is a plan view of a part of the magnetic sensor according to the second embodiment of the present invention. Fig. 24 is a side view showing a part of the magnetic sensor according to the second embodiment of the present invention. Fig. 25 is a plan view showing a main part of the magnetic sensor according to the second embodiment of the present invention. Fig. 26 is a sectional view showing a part of a section at a position indicated by the line 26-26 in Fig. 25 is displayed. Fig. 27 is a sectional view showing a part of a section at a position indicated by the line 27-27 in Fig. 25 is specified. Fig. 28 is a plan view showing a main part of a magnetic sensor according to a third embodiment of the present invention. Fig. 29 is a sectional view showing a part of a section at a position indicated by the line 29-29 in Fig. 28 is specified. Fig. 30 is a sectional view showing a part of a section at a position shown in Fig. 28 is marked by the line 30-30-. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, some embodiments and modification examples of the disclosure will be described in detail with reference to the accompanying drawings. Note that the following description refers to illustrative examples of the disclosure and should not be construed as limiting the technology. Factors including, without limitation, numerical values, shapes, materials, components, positions of the components, and the manner in which the components are coupled to each other are for illustrative purposes only and should not be construed as limiting the technology. Furthermore, elements in the following embodiments that are not recited in any of the broadest independent claims of the disclosure are optional and may be provided as needed. The drawings are schematic and not to be considered to scale.Similar elements are designated by the same reference numerals to avoid redundant descriptions. [First embodiment]

[0012] First, a configuration of a magnetic sensor device including a magnetic sensor according to a first embodiment of the present invention will be described with reference to FIG. Fig. 1 and Fig. 2 described. Fig. 1 is a perspective view showing the magnetic sensor device in the present embodiment. Fig. 2 is a functional block diagram showing a configuration of the magnetic sensor device in the present embodiment.

[0013] A magnetic sensor device 100 in the present embodiment includes a magnetic sensor 1 according to the present embodiment and a processor 2. The magnetic sensor 1 is configured to detect a target magnetic field, which is a magnetic field to be detected by the magnetic sensor 1, and to generate at least one detection signal. The magnetic sensor 1 may be a geomagnetic sensor that detects a geomagnetic field, a magnetic sensor for angle sensors or magnetic encoders that detects a rotating magnetic field, or a magnetic sensor for current sensors that detects a magnetic field generated by a current to be detected.

[0014] The processor 2 is configured to generate at least one detection value corresponding to the target magnetic field based on at least one detection signal. The processor 2 is implemented, for example, by an application-specific integrated circuit (ASIC).

[0015] The magnetic sensor 1 and the processor 2 each have the shape of a chip having a rectangular parallelepiped shape. The magnetic sensor 1 has an upper surface 1a and a lower surface 1b located on opposite sides, as well as four side surfaces connecting the upper surface 1a and the lower surface 1b. The processor 2 has an upper surface 2a and a lower surface 2b located on opposite sides, as well as four side surfaces connecting the upper surface 2a and the lower surface 2b. The magnetic sensor 1 is mounted on the upper surface 2a of the processor 2 such that the lower surface 1b of the magnetic sensor 1 faces the upper surface 2a of the processor 2. The magnetic sensor 1 is attached to the processor 2, for example, with an adhesive.

[0016] Here X, Y and Z directions are as in Fig. 1. The X, Y, and Z directions are orthogonal to each other. In the present embodiment, the Z direction is a direction perpendicular to the upper surface 1a of the magnetic sensor 1 and from the lower surface 1b to the upper surface 1a of the magnetic sensor 1. The directions opposite to the X, Y, and Z directions are referred to as the -X, -Y, and -Z directions, respectively.

[0017] Hereinafter, the term "top" refers to positions located in front of a reference position in the Z direction, and "bottom" refers to positions located on one side of the reference position opposite "top." With respect to the components of the magnetic sensor 1, the surface located at the end in the Z direction is referred to as the "upper surface," and the surface located at the end of the Z direction is referred to as the "lower surface." The expression "when viewed in a predetermined direction (e.g., the Z direction)" means that an object is viewed at a position distant along the predetermined direction or in a direction parallel to the predetermined direction.

[0018] The magnetic sensor 1 has a plurality of first contact surfaces (electrode contact surfaces) provided on the upper surface 1a. The processor 2 has a plurality of second contact surfaces (electrode contact surfaces) provided on the upper surface 2a. In the magnetic sensor 1, two corresponding contact surfaces of the plurality of first contact surfaces and the plurality of second contact surfaces are connected to each other by a bonding wire.

[0019] The magnetic sensor 1 has a first detection circuit 10 and a second detection circuit 20. The first and second detection circuits 10 and 20 and the processor 2 are connected via a plurality of first contact surfaces, a plurality of second contact surfaces, and a plurality of bonding wires.

[0020] Each of the first and second detection circuits 10 and 20 includes a plurality of magnetic detection elements. In the present embodiment, the plurality of magnetic detection elements are, in particular, a plurality of magnetoresistive elements. Magnetoresistive elements are hereinafter referred to as MR elements.

[0021] The first detection circuit 10 detects a component in a direction parallel to the X direction of the target magnetic field and generates at least one first detection signal corresponding to this component. The second detection circuit 20 detects a component in a direction parallel to the Y direction of the target magnetic field and generates at least one second detection signal corresponding to this component.

[0022] Next, a circuit configuration of the magnetic sensor 1 will be described with reference to Fig. 3 described. Fig. 3 is a circuit diagram showing the circuit configuration of the magnetic sensor 1.

[0023] The first detection circuit 10 includes four resistance sections R11, R12, R13, and R14, a power supply terminal V1, a ground terminal G1, and two output terminals E11 and E12. The resistance section R11 is provided between the power supply terminal V1 and the output terminal E11. The resistance section R12 is provided between the output terminal E11 and the ground terminal G1. The resistance section R13 is provided between the output terminal E12 and the ground terminal G1. The resistance section R14 is provided between the power supply terminal V1 and the output terminal E12. A voltage or current of a predetermined magnitude is applied to the power supply terminal V1. The ground terminal G1 is connected to ground.

[0024] The second detection circuit 20 includes four resistance sections R21, R22, R23, and R24, a power supply terminal V2, a ground terminal G2, and two output terminals E21 and E22. The resistance section R21 is provided between the power supply terminal V2 and the output terminal E21. The resistance section R22 is provided between the output terminal E21 and the ground terminal G2. The resistance section R23 is provided between the output terminal E22 and the ground terminal G2. The resistance section R24 is provided between the power supply terminal V2 and the output terminal E22. A voltage or current of a specific magnitude is applied to the power supply terminal V2. The ground terminal G2 is connected to ground.

[0025] The respective configurations of the first and second detection circuits 10 and 20 will be described below with reference to the Fig. 4 to 6. Fig. 4 is a perspective view showing a part of the first detection circuit 10. Fig. 5 is a plan view showing a part of the first detection circuit 10. Fig. 6 is a plan view showing a part of the second detection circuit 20.

[0026] The magnetic sensor 1 further includes a substrate 30. The magnetic sensor 1 is constructed by forming a plurality of components other than the substrate 30 on the substrate 30. The first detection circuit 10 and the second detection circuit 20 are provided on the substrate 30. Each of the resistance sections R11 to R14 includes a plurality of MR elements 50A. Each of the resistance sections R21 to R24 includes a plurality of MR elements 50B.

[0027] Each of the resistance sections R11 to R14 further comprises a plurality of lower electrodes 61 and a plurality of upper electrodes 62. As shown in the Fig. 4 and Fig. As shown in Figure 5, each of the plurality of MR elements 50A has a shape that is long in a direction parallel to the Y direction. Each of the plurality of lower electrodes 61 electrically connects two adjacent MR elements 50A in a direction parallel to the X direction. Each of the plurality of upper electrodes 62 electrically connects the two adjacent MR elements 50A mounted on two lower electrodes 61. The plurality of MR elements 50A arranged in a row parallel to the X direction are thereby connected in series.

[0028] Each of the resistance sections R11 to R14 further includes a plurality of connection electrodes (not shown). In each of the resistance sections R11 to R14, the plurality of connection electrodes electrically connect the plurality of lower electrodes 61 or the plurality of upper electrodes 62, so that a group of the plurality of MR elements 50A arranged in a row is connected in series. With such a configuration, each of the resistance sections R11 to R14 includes the plurality of MR elements 50A connected in series by the plurality of lower electrodes 61, the plurality of upper electrodes 62, and the plurality of connection electrodes.

[0029] The above description of the connection relationship of the plurality of MR elements 50A is also fundamentally applicable to the plurality of MR elements 50B of each of the resistance sections R21 to R24. As in Fig. As shown in Figure 6, in each of the resistance sections R21 to R24, each of the plurality of MR elements 50B has a shape that is long in a direction parallel to the X direction. In the above description of the connection relationship of the plurality of MR elements 50A, a connection relationship of the plurality of MR elements 50B is described when the plurality of MR elements 50A, the X direction, and the Y direction are replaced by the plurality of MR elements 50B, the Y direction, and the X direction, respectively.

[0030] Each of the resistance sections R11 to R14 further includes a plurality of magnetic field generators 70A. The plurality of magnetic field generators 70A includes a plurality of pairs of magnetic field generators 70A, each pair including two magnetic field generators 70A. The two magnetic field generators 70A are mounted at a distance from each other in a direction parallel to the Y direction, with an MR element 50A disposed therebetween. The two magnetic field generators 70A are configured to apply a bias magnetic field to the one MR element 50A located therebetween. This bias magnetic field has, as its main component, a component in a direction parallel to the Y direction.

[0031] Each of the resistance sections R21 to R24 further includes a plurality of magnetic field generators 70B. The plurality of magnetic field generators 70B includes a plurality of pairs of magnetic field generators 70B, each pair including two magnetic field generators 70B. The two magnetic field generators 70B are mounted at a distance from each other in a direction parallel to the X direction, with an MR element 50B disposed therebetween. The two magnetic field generators 70B are configured to apply a bias magnetic field to the one MR element 50B located therebetween. This bias magnetic field has a component parallel to the X direction as its main component.

[0032] As in Fig. As shown in Figure 4, each of the plurality of magnetic field generators 70A may be disposed between the lower electrode 61 and the upper electrode 62. Although not shown, each of the plurality of magnetic field generators 70B may be disposed between the lower electrode 61 and the upper electrode 62.

[0033] In the present embodiment, each of the plurality of MR elements 50A and the plurality of MR elements 50B is a spin-valve MR element. The spin-valve MR element includes a magnetization-locked layer with a magnetization fixed in a specific direction, a free layer with a magnetization whose direction is variable depending on the direction of a target magnetic field, and a gap layer deposited between the magnetization-locked layer and the free layer. The spin-valve MR element may be a TMR (tunnel magnetoresistive) element or a GMR (giant magnetoresistive) element. In a TMR element, the gap layer is a tunnel barrier layer. In a GMR element, the gap layer is a non-magnetic conductive layer.The resistance of the spin-valve MR element changes depending on the angle between the magnetization direction of the free layer and the magnetization direction of the magnetization-fixed layer. The resistance is at a minimum value when the angle is 0°, and the resistance is at a maximum value when the angle is 180°. In each MR element, the free layer exhibits a shape anisotropy in which the direction of the easy axis of magnetization is orthogonal to the magnetization direction of the magnetization-fixed layer.

[0034] The spin-valve MR element may further include an antiferromagnetic layer. The antiferromagnetic layer is made of an antiferromagnetic material and creates an exchange coupling with the magnetization-fixed layer to fix the magnetization direction of the magnetization-fixed layer. The magnetization-fixed layer may be a so-called self-pinned layer (synthetic ferri-pinned layer, SFP layer). The self-pinned layer has a stacked ferri-structure in which a ferromagnetic layer, a non-magnetic intermediate layer, and a ferromagnetic layer are stacked on top of each other, and is formed by antiferromagnetic coupling of the two ferromagnetic layers. If the magnetization-fixed layer is a self-pinned layer, the antiferromagnetic layer may be omitted.

[0035] Next, the magnetization direction of the magnetization-fixed layer and the direction of the bias field are determined with reference to Fig. 3 described. In Fig. 3, a plurality of solid arrows drawn so as to overlap the resistance sections R11 to R14 and R21 to R24, respectively, represent the magnetization direction of the magnetization-resistant layer in each of the resistance sections R11 to R14 and R21 to R24. In the Fig. In the example shown in Figure 3, the direction of the principal component of the magnetization of the magnetization-fixed layer in each of the resistance sections R11 and R13 is the X direction. The direction of the principal component of the magnetization of the magnetization-fixed layer in each of the resistance sections R12 and R14 is the -X direction. The free layer in each of the resistance sections R11 to R14 exhibits a shape anisotropy in which the direction of the easy axis of magnetization is a direction parallel to the Y direction.

[0036] The direction of the principal component of the magnetization of the magnetization-resistant layer in each of the resistance sections R21 and R23 is the Y direction. The direction of the principal component of the magnetization of the magnetization-resistant layer in each of the resistance sections R22 and R24 is the -Y direction. The free layer in each of the resistance sections R21 to R24 exhibits a shape anisotropy in which the direction of the easy axis of magnetization is a direction parallel to the X direction.

[0037] In Fig. In Figure 3, the arrows labeled M11, M12, M13, and M14 indicate the directions of the main components of the bias magnetic fields generated by the plurality of magnetic field generators 70A of the resistance sections R11, R12, R13, and R14. The direction of the main component of the bias magnetic field at the resistance sections R11 and R12 is the Y direction. The direction of the main component of the bias magnetic field at the resistance sections R13 and R14 is the -Y direction.

[0038] In Fig. In Figure 3, the majority of unfilled arrows drawn to overlap the resistance portions R11 to R14 represent the magnetization direction of the free layer in each of the resistance portions R11 to R14 in a case where the target magnetic field is not applied to the magnetic sensor 1. The direction of the main component of the magnetization of the free layer in each of the resistance portions R11 and R12 is the Y direction and is the same as the direction of the main component of the bias magnetic field at the resistance portions R11 and R12. The direction of the main component of the magnetization of the free layer in each of the resistance portions R13 and R14 is the -Y direction and is the same as the direction of the main component of the bias magnetic field at the resistance portions R13 and R14.

[0039] In Fig. In Figure 3, arrows labeled M21, M22, M23, and M24 indicate the directions of the main components of the bias magnetic fields generated by the plurality of magnetic field generators 70B in the resistance sections R21, R22, R23, and R24. The direction of the main component of the bias magnetic field at the resistance sections R21 and R22 is the X direction. The direction of the main component of the bias magnetic field at the resistance sections R23 and R24 is the -X direction.

[0040] In Fig. In Figure 3, the majority of unfilled arrows drawn to overlap the resistance sections R21 to R24 represent the magnetization direction of the free layer in each of the resistance sections R21 to R24 in a case where the target magnetic field is not applied to the magnetic sensor 1. The direction of the main component of the magnetization of the free layer in each of the resistance sections R21 and R22 is the X direction and is the same as the direction of the main component of the bias magnetic field at the resistance sections R21 and R22. The direction of the main component of the magnetization of the free layer in each of the resistance sections R23 and R24 is the -X direction and is the same as the direction of the main component of the bias magnetic field at the resistance sections R23 and R24.

[0041] Note that the magnetization direction may coincide with the direction of the principal component of magnetization mentioned above, or may deviate slightly from the direction of the principal component of magnetization. Similarly, the direction of the bias magnetic field may coincide with the direction of the principal component of the bias magnetic field mentioned above, or may deviate slightly from the direction of the principal component of the bias magnetic field. In the following description, it is assumed that the magnetization direction coincides with the direction of the principal component of magnetization, and that the direction of the bias magnetic field coincides with the direction of the principal component of the bias magnetic field.

[0042] The functions of the first and second detection circuits 10 and 20 will be explained below with reference to Fig. 3. In the first detection circuit 10, the potential of the junction point between the resistance sections R11 and R12, i.e., the potential of the output terminal E11, and the potential of the junction point between the resistance sections R13 and R14, i.e., the potential of the output terminal E12, change depending on the strength of the component in a direction parallel to the X direction of the target magnetic field. The first detection circuit 10 may generate a signal corresponding to the potential of the output terminal E11 and a signal corresponding to the potential of the output terminal E12, respectively, as a first detection signal. Alternatively, the first detection circuit 10 may generate a signal corresponding to the potential difference between the output terminals E11 and E12 as the first detection signal.In this case, the first detection circuit 10 may further comprise a differential amplifier (difference detector) which outputs the signal corresponding to the potential difference between the output terminals E11 and E12 as the first detection signal.

[0043] In the second detection circuit 20, the potential of the junction point between the resistance sections R21 and R22, i.e., the potential of the output terminal E21, and the potential of the junction point between the resistance sections R23 and R24, i.e., the potential of the output terminal E22, change depending on the strength of the component in a direction parallel to the Y direction of the target magnetic field. The second detection circuit 20 can generate a signal corresponding to the potential of the output terminal E21 and a signal corresponding to the potential of the output terminal E22, respectively, as a second detection signal. Alternatively, the second detection circuit 20 can generate a signal corresponding to the potential difference between the output terminals E21 and E22 as the second detection signal.In this case, the second detection circuit 20 may further comprise a differential amplifier (difference detector) that outputs the signal corresponding to the potential difference between the output terminals E21 and E22 as a second detection signal.

[0044] Next, configurations of the plurality of MR elements 50A, the plurality of MR elements 50B, the plurality of magnetic field generators 70A, and the plurality of magnetic field generators 70B will be described with reference to FIG. Fig. 7 to 10 are described in detail. Fig. 7 is a plan view showing a main part of the magnetic sensor 1. Fig. Figure 8 is a plan view showing the MR element, the magnetic field generators, and an insulator layer. Fig. 9 is a sectional view showing a part of a section at a position shown in Fig. 7 is marked by line 9-9. Fig. 10 is a sectional view showing a part of a section at a position shown in Fig. 7 is marked by the 10-10 line.

[0045] Here, a first direction D1 and a second direction D2, which are each orthogonal to the Z direction and orthogonal to each other, are defined as shown in the Fig. 7 to 10. In the first detection circuit 10, the first direction D1 is a direction parallel to the Y direction, and the second direction D2 is a direction parallel to the X direction. In the second detection circuit 20, the first direction D1 is a direction parallel to the X direction, and the second direction D2 is a direction parallel to the Y direction.

[0046] Hereinafter, each MR element of the plurality of MR elements 50A and the plurality of MR elements 50B is denoted by reference numeral 50, and each magnetic field generator of the plurality of magnetic field generators 70A and the plurality of magnetic field generators 70B is denoted by reference numeral 70. The magnetic sensor 1 includes at least one MR element 50. In the present embodiment, the magnetic sensor 1 specifically includes a plurality of MR elements 50 as the at least one MR element 50.

[0047] Here, configurations of the MR element 50 and the magnetic field generator 70 are described, focusing on one MR element 50. The MR element 50 includes a plurality of magnetic films. The stacking direction of the plurality of magnetic films is a direction parallel to the Z direction. The plurality of magnetic films includes a magnetization-resistant layer 52 and a free layer 54. Each of the plurality of MR elements 50 further includes a gap layer 53, a buffer layer 51, and a cap layer 55. As shown in the Fig. 9 and Fig. As shown in Figure 10, the buffer layer 51, the magnetization-resistant layer 52, the gap layer 53, the free layer 54, and the cap layer 55 are stacked in this order in the Z direction. Both the buffer layer 51 and the cap layer 55 are formed of a non-magnetic metallic material such as Ru, Ta, Cu, or Cr.

[0048] The MR element 50 has an upper surface 50a located at the end in the Z direction, a lower surface 50b located at the end in the -Z direction, two side surfaces 50c located at two ends in the first direction D1, and two side surfaces 50d located at two ends in the second direction D2. The lower surface 50b of the MR element 50 is in contact with the lower electrode 61. Each of the two side surfaces 50c and the two side surfaces 50d is inclined with respect to the stacking direction (direction parallel to the Z direction) of the plurality of magnetic films.

[0049] The magnetic sensor 1 further comprises at least one ferromagnetic layer 72 made of a ferromagnetic material and an insulator layer 32 made of an insulating material such as Al2O3 or SiO2. The at least one ferromagnetic layer 72 is applied such that it overlaps the MR element 50 when viewed in the first direction D1. In the present embodiment, the at least one ferromagnetic layer 72 is applied such that it completely overlaps the free layer 54 when viewed in the first direction D1.

[0050] The at least one ferromagnetic layer 72 is applied such that it rests on a side surface 50c of the MR element 50. A portion of the at least one ferromagnetic layer 72 overlaps a portion of the MR element 50 when viewed in the Z direction. The insulating layer 32 is applied to two sides of the MR element 50 in the second direction D2.

[0051] In the present embodiment, the MR element 50 is specifically deposited between two ferromagnetic layers 72 spaced apart from each other in the first direction D1. The insulator layer 32 is deposited around the MR element 50 and the two ferromagnetic layers 72.

[0052] The ferromagnetic layer 72 consists of a ferromagnetic material containing one or more elements from the group consisting of Co, Fe, and Ni. Examples of such a ferromagnetic material include CoFe, CoFeB, and CoNiFe. The ferromagnetic layer 72 can be formed from a stack of two or more layers, in which two adjacent layers each consist of different ferromagnetic materials. Examples of such a stack forming the ferromagnetic layer 72 include a stack of a Co layer, a CoFe layer, and a Co layer, as well as a stack of a Co70 Fe 30 -layer, a co 30 Fe 70 -layer and a co 70 Fe 30 -layer. Note that Co 70 Fe 30 stands for an alloy containing 70 atomic percent Co and 30 atomic percent Fe, and Co 30 Fe 70 for an alloy containing 30 atomic percent Co and 70 atomic percent Fe.

[0053] The magnetic sensor 1 further includes two buffer layers 71, each deposited on the lower surface (Z-direction side) of a plurality of the two ferromagnetic layers 72. The two buffer layers 71 are formed of a non-magnetic metallic material such as Ru, Ta, Cu, or Cr.

[0054] The magnetic sensor 1 further includes an antiferromagnetic layer 74 deposited on the MR element 50, the two ferromagnetic layers 72, and the insulator layer 32, as well as a cover layer 75 deposited on the antiferromagnetic layer 74. The antiferromagnetic layer 74 includes two antiferromagnetic portions 74a facing the two ferromagnetic layers 72 and a non-facing portion 74b facing the MR element 50 and the insulator layer 32, but not the two ferromagnetic layers 72. The two antiferromagnetic portions 74a are connected to each other by the non-facing portion 74b. There is no magnetic layer between the MR element 50 and the antiferromagnetic layer 74. The cover layer 75 has two protective parts 75a which are applied to the two antiferromagnetic parts 74a.

[0055] The antiferromagnetic layer 74 is formed from an antiferromagnetic material such as IrMn or PtMn. The cover layer 75 is formed from a non-magnetic metallic material such as Ru, Ta, Cu, or Cr.

[0056] The buffer layer 71 and the ferromagnetic layer 72 form a first stack 701. The antiferromagnetic layer 74 and the cap layer 75 form a second stack 702. The MR element 50 is deposited between two first stacks 701. The second stack 702 is deposited on the MR element 50, the insulator layer 32, and the two first stacks 701.

[0057] The second stack 702 comprises two stacked portions 702a deposited on the two first stacks 701. Each of the two stacked portions 702a comprises an antiferromagnetic portion 74a and a protective portion 75a.

[0058] The ferromagnetic layer 72 has a total magnetization. The total magnetization of the ferromagnetic layer 72 is a volume-averaged vector sum of the magnetic moments for each unit of atoms, crystal lattices, etc., in the entire ferromagnetic layer 72. Hereinafter, the total magnetization of the ferromagnetic layer 72 is simply referred to as the magnetization of the ferromagnetic layer 72. In a stack comprising the first stack 701 and a stacked part 702a deposited on the first stack 701, the antiferromagnetic part 74a is in contact with the upper surface of the ferromagnetic layer 72 to be exchange-coupled with the ferromagnetic layer 72. This defines the magnetization direction of the ferromagnetic layer 72.The ferromagnetic layer 72 and the antiferromagnetic portion 74a can form the magnetic field generator 70, which generates a bias magnetic field applied to the MR element 50 based on the magnetization of the ferromagnetic layer 72. The magnetic field generator 70 thus formed is highly resistant to magnetic interference fields.

[0059] Since the ferromagnetic layer 72 is part of the first stack 701 and the antiferromagnetic part 74a is part of the stacked part 702a, the first stack 701 and the stacked part 702a can be said to form the magnetic field generator 70. The magnetic field generator 70 includes the buffer layer 71, the ferromagnetic layer 72, the antiferromagnetic part 74a, and the protective part 75a. The MR element 50 is disposed between two magnetic field generators 70. The two magnetic field generators 70 cooperate to apply a bias magnetic field to the MR element 50. The magnetization direction of the ferromagnetic layer 72 of one of the two magnetic field generators 70 may be the same as the magnetization direction of the ferromagnetic layer 72 of the other of the two magnetic field generators 70.In this case, the direction of the bias magnetic field generated by one of the two magnetic field generators 70 becomes the same as the direction of the bias magnetic field generated by the other of the two magnetic field generators 70.

[0060] The upper surface 50a of the MR element 50 faces the non-facing portion 74b of the antiferromagnetic layer 74. The distance between at least a portion of the non-facing portion 74b and the lower surface 50b of the MR element 50 may be the same as the distance between the upper surface 50a and the lower surface 50b. The distance between the antiferromagnetic portion 74a of the antiferromagnetic layer 74 and the upper surface of the lower electrode 61 may be the same as the distance between the non-facing portion 74b and the lower surface 50b, or it may be different from the distance between the non-facing portion 74b and the lower surface 50b. In the latter case, the maximum distance between the antiferromagnetic part 74a and the upper surface of the lower electrode 61 may be larger or smaller than the distance between the non-facing part 74b and the lower surface 50b.

[0061] The ferromagnetic layer 72 has a side surface 72a facing the side surface 50c of the MR element 50. The side surface 72a has an inclined portion 72a1 facing the free layer 54 of the MR element 50 and inclined with respect to the stacking direction (a direction parallel to the Z direction) of the plurality of magnetic films. The angle formed by the inclined portion 72a1 with respect to the stacking direction is in a range of equal to or greater than 20° and equal to or less than 90°.

[0062] The magnetic sensor 1 further comprises an insulator layer 31 formed of an insulating material, which is sandwiched between the substrate 30 (see Fig. 4 to 6) and the lower electrode 61, and an insulator layer 33 made of an insulating material disposed between the MR element 50 and the two first stacks 701. The insulator layers 31 and 33 are formed of an insulating material such as Al2O3 or SiO2.

[0063] The upper surface of the second stack 702, i.e., the upper surface of the cover layer 75, is in contact with the upper electrode 62. The planar shape of the second stack 702 (viewed in the Z direction) can be the same as, smaller than, or larger than the planar shape of the upper electrode 62. The magnetic sensor 1 further comprises an insulator layer (not shown) made of an insulating material, which is applied to the upper electrode 62.

[0064] So far, the configurations of the MR element 50 and the magnetic field generator 70 have been described with emphasis on one MR element 50. In the present embodiment, the magnetic sensor 1 has a plurality of MR elements 50. As shown in Fig. 7, the plurality of MR elements 50 comprises two MR elements 50 arranged along the second direction D2. The second stack 702 is arranged between the two MR elements 50 and the upper electrode 62, which electrically connects the two MR elements 50. In the Fig. In the example shown in Figure 7, the second stack 702 is applied to the two MR elements 50 and four first stacks 701. In this example, the second stack 702 has four stacked parts 702a.

[0065] The two MR elements 50 are also electrically connected by the antiferromagnetic layer 74 of the second stack 702. The two MR elements 50 can be connected in series by the antiferromagnetic layer 74.

[0066] Since the magnetic sensor 1 in the present embodiment includes the plurality of MR elements 50 and a plurality of magnetic field generators 70, the magnetic sensor 1 includes a plurality of buffer layers 71, a plurality of ferromagnetic layers 72, a plurality of antiferromagnetic layers 74, and a plurality of cap layers 75.

[0067] Next, the operation and effect of the magnetic sensor 1 according to the present embodiment will be described. In the present embodiment, the antiferromagnetic layer 74 is deposited on the MR element 50, the two ferromagnetic layers 72, and the insulator layer 32. There is no magnetic layer between the MR element 50 and the antiferromagnetic layer 74. According to the present embodiment, this makes it possible to limit the reduction in the sensitivity of the MR element 50.

[0068] In the present embodiment, the antiferromagnetic layer 74 includes the antiferromagnetic portion 74a, which is exchange-coupled with the ferromagnetic layer 72 to define the magnetization direction of the ferromagnetic layer 72. As described below, in the present embodiment, the underlying portion on which the antiferromagnetic layer 74 is formed is flat or nearly flat, and the antiferromagnetic layer 74 can be formed in a state where no structures are present on the underlying portion. According to the present embodiment, the layer thickness of the antiferromagnetic portion 74a can therefore be prevented from becoming small.According to the present embodiment, this enables the effective use of the antiferromagnetic part 74a, and as a result, the above-described function of the antiferromagnetic part 74a and the function of the magnetic field generator 70 can be realized.

[0069] In the present embodiment, the cap layer 75 is formed on the antiferromagnetic layer 74. The cap layer 75 includes the protective portion 75a that protects the antiferromagnetic portion 74a. According to the present embodiment, by forming the cap layer 75 on the antiferromagnetic layer 74, the film thickness of the protective portion 75a can be prevented from becoming small. According to the present embodiment, this enables effective use of the protective portion 75a, and as a result, the above-described function of the protective portion 75a can be realized.

[0070] The above-described effect will be described in detail below, in comparison with a magnetic sensor of a comparative example including a magnetic field generator of the comparative example. First, a configuration of the magnetic sensor of the comparative example will be described. The magnetic sensor of the comparative example includes a magnetic field generator 170 of the comparative example instead of the magnetic field generator 70 of the present embodiment.

[0071] The magnetic field generator 170 includes a buffer layer 171, a ferromagnetic layer 172, an antiferromagnetic layer 173, and a cap layer 174. The buffer layer 171, the ferromagnetic layer 172, the antiferromagnetic layer 173, and the cap layer 174 correspond, respectively, to the buffer layer 71, the ferromagnetic layer 72, the antiferromagnetic layer 74, and the cap layer 75 in the present embodiment. In the comparative example, the antiferromagnetic layer 173 is in contact with the upper surface of the ferromagnetic layer 172 to be exchange-coupled with the ferromagnetic layer 172. This fixes the magnetization direction of the ferromagnetic layer 172.

[0072] Fig. Figure 11 is a sectional view showing a method for manufacturing the magnetic field generator of the comparative example. The magnetic field generator 170 of the comparative example is manufactured as follows. First, a stacked film, which later forms the MR element 50, is patterned to form the two side surfaces 50d (see Fig. 10) on this stacked film. Next, the insulator layer 32 (see Fig. 8 and Fig. 10) formed around the stacked film.

[0073] Next, a photoresist mask 81 is formed on the stacked film as shown in Fig. 11. Next, the photoresist mask 81 is used to pattern the stacked film by etching, so that the two side surfaces 50c are formed on the stacked film. This transforms the stacked film into the MR element 50.

[0074] Next, leaving the photoresist mask 81 in place, the insulator layer 131, the buffer layer 171, the ferromagnetic layer 172, the antiferromagnetic layer 173, and the cap layer 174 are formed in this order. This completes the magnetic field generator 170. Next, the photoresist mask 81 is removed. Note that the photoresist mask 81 can be formed after the patterning of the MR element 50.

[0075] As in Fig. As shown in Figure 11, the film thickness of the antiferromagnetic layer 173 decreases with decreasing distance from the photoresist mask 81 due to the influence of the shadow of the photoresist mask 81. Therefore, near a corner at the point where the top surface 50a and the side surface 50c of the MR element 50 intersect, the barrier temperature of the antiferromagnetic layer 173 decreases, and the thermal resistance of the antiferromagnetic layer 173 decreases. Therefore, the function of the antiferromagnetic layer 173 and the function of the magnetic field generator 170 cannot be performed in an environment where the temperature is temporarily or for a long time high.

[0076] Similarly, the thickness of the cap layer 174 decreases with decreasing distance from the photoresist mask 81 due to the influence of the shadow of the photoresist mask 81. Therefore, the antiferromagnetic layer 173 near the above-described corner cannot be sufficiently protected, which poses a corrosion risk to the antiferromagnetic layer 173. If the antiferromagnetic layer 173 corrodes, the function of the antiferromagnetic layer 173 and the function of the magnetic field generator 170 cannot be fulfilled.

[0077] In contrast, in the present embodiment, it is possible to prevent the film thickness of the antiferromagnetic part 74a and the protective part 75a from decreasing. Fig. 12A and Fig. 12B are each a sectional view showing a method for manufacturing the magnetic field generator 70 in the present embodiment. The magnetic field generator 70 in the present embodiment is formed as follows. First, a stacked film, which later becomes the MR element 50, is patterned to form the two side surfaces 50d (see Fig. 10) on the stacked film. Next, the insulator layer 32 (see Fig. 8 and Fig. 10) formed around the stacked film.

[0078] Next, a photoresist mask 82 is formed on the stacked film as shown in Fig. 12A. Next, the photoresist mask 82 is used to pattern the stacked film by etching, so that the two side surfaces 50c are formed on the stacked film. This transforms the stacked film into the MR element 50. Then, while leaving the photoresist mask 82, the insulator layer 33, the buffer layer 71, and the ferromagnetic layer 72 are formed in this order.

[0079] Next, the photoresist mask 82 is removed as shown in Fig. 12B. Next, the antiferromagnetic layer 74 and the cap layer 75 are formed in this order over the MR element 50, the ferromagnetic layer 72, and the insulator layer 32. Subsequently, the magnetization direction of the ferromagnetic layer 72 is fixed. Thus, the magnetic field generator 70 is completed. A method for fixing the magnetization direction of the ferromagnetic layer 72 will be described in detail later.

[0080] As in Fig. As shown in Fig. 12B, in the present embodiment, the antiferromagnetic layer 74 and the cap layer 75 are formed over the stack of the MR element 50, the ferromagnetic layer 72, and the insulator layer 32. The upper surface of this stack is flat or nearly flat. When the antiferromagnetic layer 74 and the cap layer 75 are formed, no structures such as a photoresist mask are present on the stack. Due to these factors, in the present embodiment, the film thickness of the antiferromagnetic layer 74 and the cap layer 75 is constant or nearly constant regardless of the distance from the MR element 50. Thus, according to the present embodiment, it is possible to prevent the film thickness of the antiferromagnetic part 74a and the protection part 75a from becoming smaller. As a result, according to the present embodiment, it is possible to effectively utilize the antiferromagnetic part 74a and the protection part 75a.

[0081] In the present embodiment, the insulator layer 32 functions to limit variations in the thickness of each of the layers formed above the MR element 50. In other words, if the insulator layer 32 were not present, a portion of the antiferromagnetic layer 74 and the cap layer 75 would each be formed along the two side surfaces 50d of the MR element 50. In this case, the thickness of each of the layers formed along the two side surfaces 50d of the MR element 50 may differ from the thickness of each of the layers formed along the top surface 50a of the MR element 50 and the top surface of the ferromagnetic layer 72.In contrast, according to the present embodiment, it is possible to restrict the change in the film thickness of each of the layers by forming each of the antiferromagnetic layer 74 and the cap layer 75 along the upper surface 50a of the MR element 50, the upper surface of the ferromagnetic layer 72, and the upper surface of the insulator layer 32. Furthermore, it is possible to more effectively restrict the change in the film thickness of each of the layers by forming each of the antiferromagnetic layer 74 and the cap layer 75 by a method with good step coverage. According to the present embodiment, this also enables effective use of the antiferromagnetic part 74a and the protective part 75a.

[0082] Next, a method for forming the plurality of MR elements 50 in the present embodiment will be briefly described. In the method for forming the plurality of MR elements 50, a plurality of initial MR elements are first formed, which later become the plurality of MR elements 50. Each of the plurality of initial MR elements includes an initial magnetization-resistant layer, which later becomes the magnetization-resistant layer 52, the buffer layer 51, the gap layer 53, the free layer 54, and the cap layer 55.

[0083] Next, the magnetization direction of the initial magnetization-fixed layer is fixed in a predetermined direction using laser light and an external magnetic field having a component in the predetermined direction described above. For example, in a plurality of initial MR elements that later become the plurality of MR elements 50A constituting the resistance portions R11 and R13 of the first detection circuit 10, the plurality of initial MR elements are irradiated with the laser light while an external magnetic field is applied in the X direction. When the laser light irradiation is completed, the magnetization direction of the initial magnetization-fixed layer is fixed in the X direction. This causes the initial magnetization-fixed layer to become the magnetization-fixed layer 52, and the initial MR element to become the MR element 50A.

[0084] In a plurality of initial MR elements, which later become the plurality of MR elements 50A constituting the resistance portions R12 and R14 of the first detection circuit 10, the magnetization direction of the initial magnetization-fixed layer of each of the plurality of initial MR elements can be fixed in the -X direction by using an external magnetic field in the -X direction. In this way, the plurality of MR elements 50A are formed. The plurality of MR elements 50B constituting each of the resistance portions R21 to R24 of the second detection circuit 20 are also formed by the same method as the plurality of MR elements 50A.

[0085] Next, a method for fixing the magnetization direction of the ferromagnetic layer 72 will be described. The magnetization direction of the ferromagnetic layer 72 is fixed by the same method as that of the magnetization-fixed layer 52 of the MR element 50. In other words, as described with reference to Fig. 12A and Fig. As described in FIG. 12B, first, the antiferromagnetic layer 74 and the cap layer 75 are formed, and then the magnetization direction of the ferromagnetic layer 72 is fixed in the above-described predetermined direction using the laser light and the external magnetic field having a component in the predetermined direction. For example, for the plurality of ferromagnetic layers 72 deposited near the plurality of MR elements 50A that will later form the resistance portions R11 and R12 of the first detection circuit 10, the plurality of ferromagnetic layers 72 are irradiated with the laser light while an external magnetic field in the Y direction is applied to the plurality of ferromagnetic layers 72. When the laser light irradiation is completed, the magnetization direction of the ferromagnetic layer 72 is fixed in the Y direction.

[0086] For the plurality of ferromagnetic layers 72 deposited near the plurality of MR elements 50A, which will later form the resistance portions R13 and R14 of the first detection circuit 10, the magnetization direction of each of the plurality of ferromagnetic layers 72 can be fixed in the -Y direction by using an external magnetic field in the -Y direction. The magnetization direction of the plurality of ferromagnetic layers 72 deposited near the plurality of MR elements 50B, which will later form the resistance portions R21 to R24 of the second detection circuit 20, is also fixed by the same method mentioned above.

[0087] Note that the intensity of the laser light used to fix the magnetization direction of the ferromagnetic layer 72 may be lower than the intensity of the laser light used to fix the magnetization direction of the magnetization-fixed layer 52. The intensity of the laser light used to fix the magnetization direction of the ferromagnetic layer 72 may be such that the change in the magnetoresistive change rate, which is the ratio of the magnetoresistive change to the resistance of the MR element 50, is limited. [Modification examples]

[0088] Next, the first to seventh modification examples of the magnetic sensor 1 of the present embodiment will be described. First, the first modification example will be described with reference to Fig. 13 described. Fig. 13 is a plan view showing a main part of the first modification example of the magnetic sensor 1. In the first modification example, each of the plurality of lower electrodes 61 electrically connects two adjacent MR elements 50 in the first direction D1. Each of the plurality of upper electrodes 62 electrically connects two adjacent MR elements 50 deposited on two lower electrodes 61. Thereby, the plurality of MR elements 50 arranged in a row are connected in series in the first direction D1. In the first modification example, the plurality of connecting electrodes electrically connect the plurality of lower electrodes 61 or the plurality of upper electrodes 62, so that a group of the plurality of MR elements 50 arranged in a row is connected in series.

[0089] In the first modification example, the second stack 702 is arranged between the two MR elements 50 arranged in the first direction D1 and the upper electrode 62. The two MR elements 50 are also separated by the antiferromagnetic layer 74 (see Fig. 9 and Fig. 10) of the second stack 702. The two MR elements 50 can be connected in series through the antiferromagnetic layer 74.

[0090] Next, the second modification example will be described with reference to Fig. 14 described. Fig. 14 is a plan view showing a main part of the second modification example of the magnetic sensor 1. In the second modification example, the two MR elements 50 and three magnetic field generators 70 are disposed between the lower electrode 61 and the upper electrode 62. To distinguish the three magnetic field generators 70 from each other, "first," "second," and "third" are used here. The first magnetic field generator 70 is disposed between the two MR elements 50 arranged along the first direction D1. The second magnetic field generator 70 is disposed at a position where one of the two MR elements 50 is arranged between the second magnetic field generator 70 and the first magnetic field generator 70. The third magnetic field generator 70 is disposed at a position where the other of the two MR elements 50 is arranged between the third magnetic field generator 70 and the first magnetic field generator 70.

[0091] The two in Fig. The MR elements 50 shown in Figure 14 can be connected to the same lower electrode 61 and the same upper electrode 62. The two MR elements 50 can be connected in parallel in a circuit configuration. Here, the two parallel-connected MR elements 50 are referred to as an element pair. Each of the plurality of lower electrodes 61 electrically connects two adjacent element pairs in the second direction D2. Each of the plurality of upper electrodes 62 electrically connects the two adjacent element pairs deposited on the two lower electrodes 61. As a result, the plurality of element pairs arranged in a row are connected in series in the second direction D2.

[0092] The second stack 702 is arranged between the two element pairs and the upper electrode 62, which electrically connects the two element pairs. In the second modification example, the second stack 702 is deposited on four MR elements 50 and six first stacks 701. In the second modification example, the second stack 702 has six stacked parts 702a.

[0093] Next, a third modification example will be described with reference to Fig. 15 described. Fig. 15 is a plan view showing a main part of the third modification example of the magnetic sensor 1. In the third modification example, the two MR elements 50 arranged along the second direction D2 are sandwiched between two magnetic field generators 70 arranged along the first direction D1.

[0094] The two in Fig. The MR elements 50 shown in Figure 15 are connected to the same lower electrode 61 and the same upper electrode 62. The two MR elements 50 form a parallel-connected element pair in a circuit configuration. Each of the plurality of lower electrodes 61 electrically connects two adjacent element pairs in the second direction D2. Each of the plurality of upper electrodes 62 electrically connects the two adjacent element pairs deposited on the two lower electrodes 61. As a result, the plurality of element pairs arranged in a row are connected in series in the second direction D2.

[0095] The second stack 702 is located between the two element pairs and the upper electrode 62, which electrically connects the two element pairs. In the third modification example, the second stack 702 is deposited on four MR elements 50 and four first stacks 701. In the third modification example, the second stack 702 has four stacked parts 702a.

[0096] Next, the fourth modification example will be described with reference to Fig. 16 described. Fig. 16 is a sectional view showing a main part of the fourth modification example of the magnetic sensor 1. In the fourth modification example, the first stack 701 includes, in addition to the buffer layer 71 and the ferromagnetic layer 72, an antiferromagnetic layer 76 deposited between the buffer layer 71 and the ferromagnetic layer 72. The antiferromagnetic layer 76 is formed of an antiferromagnetic material such as IrMn or PtMn.

[0097] The antiferromagnetic layer 76 is in contact with the lower surface of the ferromagnetic layer 72 to be exchange-coupled with the ferromagnetic layer 72. As mentioned above, the antiferromagnetic part 74a is exchange-coupled with the ferromagnetic layer 72. In the fourth modification example, the antiferromagnetic part 74a and the antiferromagnetic layer 76 are exchange-coupled with the ferromagnetic layer 72 to define the magnetization direction of the ferromagnetic layer 72.

[0098] Next, the fifth modification example will be described with reference to Fig. 17 described. Fig. 17 is a sectional view showing a main part of the fifth modification example of the magnetic sensor 1. In the fifth modification example, the first stack 701 includes, in addition to the buffer layer 71 and the ferromagnetic layer 72, a ferromagnetic layer 77 disposed between the buffer layer 71 and the ferromagnetic layer 72. The ferromagnetic layer 77 is formed of a ferromagnetic material containing one or more elements selected from the group consisting of Co, Fe, and Ni. In the fifth modification example, the ferromagnetic layer 77 has a magnetization in the same direction as the magnetization of the ferromagnetic layer 72.

[0099] In the fifth modification example, the ferromagnetic layer 72 may be formed of a ferromagnetic material that can increase the exchange coupling energy between the ferromagnetic layer 72 and the antiferromagnetic part 74a, and the ferromagnetic layer 77 may be formed of a ferromagnetic material that has a saturation magnetic flux density greater than that of the ferromagnetic material constituting the ferromagnetic layer 72. In this case, the strength of the bias magnetic field generated by the magnetic field generator 70 can be increased while increasing the exchange coupling energy between the ferromagnetic part formed of the ferromagnetic layers 72 and 77 and the antiferromagnetic part 74a, and the magnetic field generator 70 can be made smaller. An example of the ferromagnetic layer 72 includes a Co 70 Fe 30-layer. An example of the ferromagnetic layer 77 includes a Co 30 Fe 70 - shift.

[0100] Next, the sixth modification example will be described with reference to Fig. 18 described. Fig. 18 is a sectional view showing a main part of the sixth modification example of the magnetic sensor 1. In the sixth modification example, the first stack 701 includes, in addition to the buffer layer 71 and the ferromagnetic layer 72, a ferromagnetic layer 78 disposed between the buffer layer 71 and the ferromagnetic layer 72, and a non-magnetic layer 79 disposed between the ferromagnetic layer 72 and the ferromagnetic layer 78. The ferromagnetic layer 78 is formed of a ferromagnetic material containing one or more elements selected from the group consisting of Co, Fe, and Ni. The ferromagnetic layer 72 and the ferromagnetic layer 78 may be formed of the same ferromagnetic material or different ferromagnetic materials. The non-magnetic layer 79 is formed of a non-magnetic metallic material such as Ru.

[0101] In the sixth modification example, the ferromagnetic layer 72 and the ferromagnetic layer 78 are ferromagnetically exchange-coupled via the non-magnetic layer 79, so that they have the same magnetization direction. The ferromagnetic layer 72 and the ferromagnetic layer 78 have magnetization in the same direction. The thickness of the non-magnetic layer 79 is such that the exchange coupling between the ferromagnetic layer 72 and the ferromagnetic layer 78 is not lost.

[0102] Next, the seventh modification example will be described with reference to Fig. 19. In the seventh modification example, the two side surfaces 50c of the MR element 50 are formed by etching at least the gap layer 53, the free layer 54 and the cover layer 55 in the context of the Fig. 12A. In this process, a portion of the magnetization-resistant layer 52 may or may not be etched.

[0103] In the seventh modification example, the ferromagnetic layer 72 is deposited so that it rests on the side surface 50c of the MR element 50 and on the magnetization-resistant layer 52. The insulator layer 33 is formed along the side surface 50c of the MR element 50 and the upper surface of the magnetization-resistant layer 52.

[0104] Note that the first to seventh modification examples can be combined in any way. For example, the first one can be Fig. 13 shown modification example with the second in Fig. 14 shown modification example or the third in Fig. 15. In this case, two pairs of MR elements 50 adjacent in the first direction D1 are electrically connected. [Second embodiment]

[0105] Next, a second embodiment of the present invention will be described. First, a configuration of a magnetic sensor system including a magnetic sensor according to the present embodiment will be described with reference to Fig. 20 described. Fig. 20 is a perspective view showing a magnetic sensor system 200 in the present embodiment.

[0106] The magnetic sensor system 200 includes a magnetic sensor 201 according to the present embodiment and a magnetic field generation region 202 that generates a predetermined magnetic field. In the present embodiment, the magnetic field generation region 202 is a magnet configured to apply a partial magnetic field, which is a portion of the generated magnetic field, to the magnetic sensor 201. This partial magnetic field has a first magnetic field component Hz parallel to the Z direction and a second magnetic field component Hy parallel to the Y direction.

[0107] As in Fig. As shown in Figure 20, in the present embodiment, the magnetization direction of the magnetic field generation region 202 is the Y direction, and the direction of the second magnetic field component Hy is the -Y direction. The direction of the first magnetic field component Hz is the Z direction when the magnetic field generation region 202 moves from a predetermined position in the Y direction, and is the -Z direction when the magnetic field generation region 202 moves from the predetermined position in the -Y direction.

[0108] Next, a schematic configuration of the magnetic sensor 201 according to the present embodiment will be described with reference to Fig. 21 described. Fig. 21 is a circuit diagram showing a circuit configuration of the magnetic sensor 201.

[0109] The magnetic sensor 201 has four resistance sections R31, R32, R33, and R34, a power supply terminal V3, a ground terminal G3, and two output terminals E31 and E32. The resistance section R31 is provided between the power supply terminal V3 and the output terminal E31. The resistance section R32 is provided between the output terminal E31 and the ground terminal G3. The resistance section R33 is provided between the output terminal E32 and the ground terminal G3. The resistance section R34 is located between the power supply terminal V3 and the output terminal E32. A voltage or current of a specific magnitude is applied to the power supply terminal V3. The ground terminal G3 is connected to ground.

[0110] Each of the resistance sections R31 to R34 includes the plurality of MR elements 50. The configuration of the plurality of MR elements 50 is the same as in the first embodiment. In other words, each of the plurality of MR elements 50 includes the buffer layer 51, the magnetization-resistant layer 52, the gap layer 53, the free layer 54, and the cap layer 55, as shown in FIGS. Fig. 9 and Fig. 10 of the first embodiment.

[0111] In Fig. 21, a plurality of solid arrows drawn so as to overlap the resistance sections R31 to R34 respectively represent the magnetization direction of the magnetization-resistant layer 52 in each of the resistance sections R31 to R34. In the Fig. In the example shown in Figure 21, the direction of the main component of the magnetization of the magnetization-fixed layer 52 in each of the resistance sections R31 and R34 is the X direction. The direction of the main component of the magnetization of the magnetization-fixed layer 52 in each of the resistance sections R32 and R33 is the -X direction. The free layer 54 in each of the resistance sections R31 to R34 exhibits a shape anisotropy in which the direction of the easy axis of magnetization is parallel to the Y direction.

[0112] Each of the resistance sections R31 to R34 further includes the plurality of magnetic field generators 70. The configuration of the plurality of magnetic field generators 70 is the same as in the first embodiment. The plurality of magnetic field generators 70 includes a plurality of pairs of magnetic field generators 70, each pair including two magnetic field generators 70. The two magnetic field generators 70 are mounted at a distance from each other in a direction parallel to the Y direction, with an MR element 50 interposed therebetween. The two magnetic field generators 70 are configured to apply a bias magnetic field to the one MR element 50 located therebetween. This bias magnetic field has a component parallel to the Y direction as its main component.

[0113] In Fig. In Figure 21, the arrows labeled M31, M32, M33, and M34 indicate the directions of the main components of the bias magnetic fields generated by the plurality of magnetic field generators 70 in the resistance sections R31, R32, R33, and R34, respectively. The directions of the main components of the bias magnetic fields at the resistance sections R31 and R34 are each in the Y direction. The directions of the main components of the bias magnetic fields at the resistance sections R32 and R33 are each in the -Y direction.

[0114] In Fig. In FIG. 21, the plurality of hollow arrows drawn to overlap the resistance sections R31 to R34 represent the magnetization direction of the free layer in each of the resistance sections R31 to R34 when the partial magnetic field is not applied to the magnetic sensor 201. The direction of the main component of the magnetization of the free layer in each of the resistance sections R31 and R34 is the Y direction and is the same as the direction of the main component of the bias magnetic field at the resistance sections R31 and R34. The direction of the main component of the magnetization of the free layer in each of the resistance sections R32 and R33 is the -Y direction and is the same as the direction of the main component of the bias magnetic field at the resistance sections R32 and R33.

[0115] Next, a configuration of the magnetic sensor 201 will be described with reference to FIG. Fig. 22 to 24. Fig. 22 is a perspective view showing a part of the magnetic sensor 201. Fig. 23 is a plan view showing a part of the magnetic sensor 201. Fig. 24 is a side view showing a part of the magnetic sensor 201.

[0116] The magnetic sensor 201 further includes a substrate 230. The magnetic sensor 201 is formed by forming a plurality of components other than the substrate 230 on the substrate 230.

[0117] The magnetic sensor 201 further comprises at least one yoke formed of a soft magnetic material. The at least one yoke has a long shape in the Y direction when viewed in the Z direction. The at least one yoke generates a magnetic field component in a direction parallel to the X direction based on the Fig. 20 shown first magnetic field component Hz.

[0118] As in the Fig. Specifically, as shown in FIGS. 22 to 24, the magnetic sensor 201 in the present embodiment includes, as at least one yoke, a plurality of yokes 250 mounted so as to be arranged in the X direction. Each of the plurality of yokes 250 has, for example, a rectangular parallelepiped shape elongated in the Y direction. The plurality of yokes 250 has a same shape. Each of the plurality of yokes 250 has a first end surface 250a and a second end surface 250b located at two ends parallel to the X direction. In each of the plurality of yokes 250, the first end surface 250a is located at one end in the -X direction, and the second end surface 250b is located at one end in the X direction.

[0119] Each of the plurality of MR elements 50 is mounted at a position where a magnetic field component generated by the plurality of yokes 250 is applied. Specifically, in the present embodiment, each of the MR elements 50 is mounted near one end of each of the plurality of yokes 250 in the -Z direction. The plurality of MR elements 50 is mounted such that a group of the plurality of MR elements 50 is arranged along the first end surface 250a or the second end surface 250b of each of the plurality of yokes 250. Hereinafter, among the plurality of MR elements 50, a plurality of MR elements arranged along the first end surface 250a is denoted by reference numeral 50C, and a plurality of MR elements arranged along the second end surface 250b is denoted by reference numeral 50D.The direction of the magnetic field component received by the plurality of MR elements 50C and the direction of the magnetic field component received by the plurality of MR elements 50D are opposite to each other.

[0120] The plurality of MR elements 50C and the plurality of MR elements 50D may or may not overlap the plurality of yokes 250 when viewed in the Z direction. In the Fig. In the examples shown in Figures 22 to 24, the majority of MR elements 50C and the majority of MR elements 50D are mounted such that they do not overlap the majority of yokes 250 when viewed in the Z direction.

[0121] As in the Fig. 22 and Fig. As shown in Figure 23, of the plurality of magnetic field generators 70, a plurality of magnetic field generators mounted with an MR element 50C disposed therebetween are designated by reference numeral 70C, and a plurality of magnetic field generators mounted with an MR element 50D disposed therebetween are designated by reference numeral 70D. The magnetic sensor 201 further includes a plurality of yokes 90C and a plurality of yokes 90D, each having a magnetic layer formed of a soft magnetic material. The plurality of yokes 90C includes a plurality of pairs of yokes 90C, each pair including two yokes 90C. The two yokes 90C are mounted on two sides of an MR element 50C in a direction parallel to the X direction. The plurality of yokes 90D includes a plurality of pairs of yokes 90D, each pair including two yokes 90D.The two yokes 90D are mounted on two sides of an MR element 50D in a direction parallel to the X direction.

[0122] The plurality of yokes 90C function to guide the magnetic components generated by the plurality of yokes 250 to the plurality of MR elements 50C. The plurality of yokes 90D function to guide the magnetic components generated by the plurality of yokes 250 to the plurality of MR elements 50D.

[0123] The magnetic sensor 201 further includes a wiring part 211 that electrically connects the plurality of MR elements 50C, and a wiring part 212 that electrically connects the plurality of MR elements 50D. Each of the wiring parts 211 and 212 consists of the plurality of lower electrodes 61 and the plurality of upper electrodes 62, as well as the plurality of connecting electrodes. Note that the lower electrode 61 and the upper electrode 62 are Fig. 25 to 27, which will be described later.

[0124] The wiring part 211 includes a first wiring that electrically connects the plurality of MR elements 50C, the direction of the main component of magnetization of the magnetization-fixed layer 52 being the X direction, and a second wiring that electrically connects the plurality of MR elements 50C, the direction of the main component of magnetization of the magnetization-fixed layer 52 being the -X direction. The resistance portion R31 is formed from the plurality of MR elements 50C electrically connected by the first wiring. The resistance portion R32 is formed from the plurality of MR elements 50C electrically connected by the second wiring.

[0125] The wiring part 212 includes a third wiring that electrically connects the plurality of MR elements 50D, where the direction of the main component of magnetization of each magnetization-fixed layer 52 is the -X direction, and a fourth wiring that electrically connects the plurality of MR elements 50D, where the direction of the main component of magnetization of each magnetization-fixed layer 52 is the X direction. The resistance portion R33 is formed from the plurality of MR elements 50D electrically connected by the third wiring. The resistance portion R34 is formed from the plurality of MR elements 50D electrically connected by the fourth wiring.

[0126] Next, an operation of the magnetic sensor 201 will be described. In a state where a first magnetic field component Hz is absent and, consequently, no magnetic field components generated by the plurality of yokes 250 are present, the magnetization direction of the free layer 54 of each of the plurality of MR elements 50C and the plurality of MR elements 50D is a direction parallel to the Y direction.

[0127] When the direction of the first magnetic field component Hz is the Z direction, the direction of the magnetic field component received by each of the plurality of MR elements 50C constituting the resistance sections R31 and R32 is the X direction, and the direction of the magnetic field component received by each of the plurality of MR elements 50D constituting the resistance sections R33 and R34 is the -X direction. In this case, the magnetization direction of the free layer 54 of each of the plurality of MR elements 50C is inclined from a direction parallel to the Y direction to the X direction, and the magnetization direction of the free layer 54 of each of the plurality of MR elements 50D is inclined from a direction parallel to the Y direction to the -X direction.As a result, compared to a state where no magnetic field component is present, the resistance value of each of the plurality of MR elements 50C constituting the resistance section R31 and the resistance value of each of the plurality of MR elements 50D constituting the resistance section R33 decreases, and the resistance value of each of the plurality of MR elements 50C constituting the resistance section R32 and the resistance value of each of the plurality of MR elements 50D constituting the resistance section R34 increases. As a result, the resistance values ​​of the resistance sections R31 and R33 decrease, and the resistance values ​​of the resistance sections R32 and R34 increase.

[0128] When the direction of the first magnetic field component Hz is the -Z direction, the direction of the magnetic field component and the change in the resistance value of each of the resistance portions R31 to R34 are opposite to the above-mentioned case where the direction of the first magnetic field component Hz is the Z direction.

[0129] The amount of change in the resistance value of each of the resistance sections R31 to R34 depends on the strength of the magnetic field component received by each of the plurality of MR elements 50C and the plurality of MR elements 50D. As the strength of the magnetic field component increases, the resistance value of each of the resistance sections R31 to R34 changes such that the amount of increase or decrease in the resistance value becomes larger. As the strength of the magnetic field component decreases, the resistance value of each of the resistance sections R31 to R34 changes such that the amount of increase or decrease in the resistance value becomes smaller. The strength of the magnetic field component depends on the strength of the first magnetic field component Hz.

[0130] Therefore, when the direction and strength of the first magnetic field component Hz change, the resistance value of each of the resistance sections R31 to R34 changes either so that the resistance value of each of the resistance sections R31 and R33 increases and the resistance value of each of the resistance sections R32 and R34 decreases, or so that the resistance value of each of the resistance sections R31 and R33 decreases and the resistance value of each of the resistance sections R32 and R34 increases. This changes the potential of the junction point between the resistance sections R31 and R32, that is, the potential of the output terminal E31, and the potential of the junction point between the resistance sections R33 and R34, that is, the potential of the output terminal E32. The magnetic sensor 201 can generate a signal corresponding to the potential of the output terminal E31 and a signal corresponding to the potential of the output terminal E32, respectively, as a detection signal.Alternatively, the magnetic sensor 201 may generate a signal corresponding to the potential difference between the output terminals E31 and E32 as the detection signal. In this case, the magnetic sensor 201 may further comprise a differential amplifier (difference detector) that outputs the signal corresponding to the potential difference between the output terminals E31 and E32 as the detection signal.

[0131] The magnetic sensor system 200 can furthermore Fig. 1 and Fig. 2 in the first embodiment. The processor 2 may be configured to receive one or two detection signals output from the magnetic sensor 201 to generate a detection value corresponding to the strength of the first component of the magnetic field Hz, or a detection value corresponding to the position of the magnetic field generation region 202 (see Fig. 20).

[0132] Next, the plurality of yokes 90C and the plurality of yokes 90D are assembled with reference to the Fig. 25 to 27 described in detail. Fig. 25 is a plan view showing a main part of the magnetic sensor 201. Fig. 26 is a sectional view showing a portion of a section taken at a point defined by line 26-26 in Fig. 25 marked position. Fig. 27 is a sectional view showing a part of a section at a position indicated by a line 27-27 in Fig. 25 is specified.

[0133] Hereinafter, each of the plurality of yokes 90C and the plurality of yokes 90D is denoted by reference numeral 90. The configuration and shape of the MR element 50 and the magnetic field generator 70, as well as the positional relationship between the MR element 50 and the magnetic field generator 70, are the same as in the first embodiment. The configuration and shape of the first and second stacks 701 and 702, and the positional relationship between the MR element 50 and the first and second stacks 701 and 702 are also the same as in the first embodiment.

[0134] Here, a configuration of a yoke 90 is described, focusing on an MR element 50. Two yokes 90 are deposited on two sides of the MR element 50 in a direction parallel to the X direction. The magnetic sensor 201 further includes an insulator layer 232 formed from an insulating material such as Al2O3 or SiO2. The insulator layer 232 is deposited on two sides of the MR element 50 in a direction parallel to the X direction. In the present embodiment, the insulator layer 232 is deposited specifically around the MR element 50 and the ferromagnetic layer 72 of the magnetic field generator 70.

[0135] The two yokes 90 are embedded in the insulator layer 232. The insulator layer 232 is located between the MR element 50 and the two yokes 90, and between the lower electrode 61 and the two yokes 90. In addition to the magnetic layer, each of the two yokes 90 may include a buffer layer sandwiched between the magnetic layer and the insulator layer 232, as well as a cap layer deposited on the magnetic layer. The buffer layer and the cap layer may be formed, for example, from a non-magnetic metallic material. Each of the two yokes 90 is deposited to rest on the side surface 50d of the MR element 50. A portion of each of the two yokes 90 overlaps a portion of the MR element 50 when viewed in the Z direction.

[0136] The two yokes 90 are mounted between the two magnetic field generators 70, which are spaced apart in a direction parallel to the Y direction. The ferromagnetic layer 72 of the magnetic field generator 70 (first stack 701) is mounted such that it overlaps the two yokes 90 when viewed in the Y or -Y direction.

[0137] The ferromagnetic layer 72 is applied so that it rests on the yoke 90. A portion of the ferromagnetic layer 72 overlaps a portion of the yoke 90 when viewed in the Z direction. The magnetic sensor 201 further includes an insulator layer 233 formed from an insulating material such as Al2O3 or SiO2 and arranged between the ferromagnetic layer 72 and the yoke 90. A portion of the buffer layer 71 of the magnetic field generator 70 (first stack 701) is inserted between the ferromagnetic layer 72 and the insulator layer 233.

[0138] In the present embodiment, the antiferromagnetic layer 74 is deposited on the MR element 50, the two ferromagnetic layers 72, the two yokes 90, and the insulator layer 232. The upper surface of each of the two yokes 90 may be in contact with the antiferromagnetic layer 74. The magnetic sensor 201 further includes an insulator layer 231 formed of an insulating material such as Al2O3 or SiO2 and sandwiched between the substrate 230 (see Fig. 23) and the lower electrode 61, and an insulator layer (not shown) formed of an insulating material and deposited on the upper electrode 62.

[0139] The configuration, operation, and effects of the present embodiment are otherwise the same as those of the first embodiment. [Third Embodiment]

[0140] Next, a third embodiment of the present invention will be described with reference to the Fig. 28 to 30 described. Fig. 28 is a plan view showing a main part of a magnetic sensor according to the present embodiment. Fig. 29 is a sectional view showing a part of a section at a position indicated by a line 29-29 in Fig. 28 is marked. Fig. 30 is a sectional view showing a part of a section at a position shown in Fig. 28 is marked by a 30-30 line.

[0141] The following describes how the configuration of the magnetic sensor 201 according to the present embodiment differs from the second embodiment using an MR element 50. In the present embodiment, each of the two magnetic field generators 70 is deposited at a distance from the MR element 50. Therefore, the ferromagnetic layer 72 of each of the two magnetic field generators 70 is deposited at a distance from the MR element 50.

[0142] Each of the two magnetic field generators 70 is applied at a distance from the two yokes 90. Therefore, the ferromagnetic layer 72 of each of the two magnetic field generators 70 is applied at a distance from the two yokes 90.

[0143] In the present embodiment, the insulator layer 233 is disposed between the ferromagnetic layer 72, the lower electrode 61, and the insulator layer 232. The magnetic sensor 201 further includes an insulator layer 234 formed of an insulating material such as Al2O3 or SiO2, which is disposed between the two yokes 90, the lower electrode 61, and the insulator layer 232.

[0144] The configuration, operation, and effects of the present embodiment are otherwise the same as those of the second embodiment.

[0145] The present invention is not limited to the aforementioned embodiments, and various modifications may be made thereto. For example, the magnetic sensor of the present invention may be a magnetic sensor including the first and second detection circuits 10 and 20 in the first embodiment, and the magnetic sensor 201 according to the second embodiment as the third detection circuit. In this magnetic sensor, the third detection circuit (magnetic sensor 201) may also be configured to detect a component in a direction parallel to the Z direction of the target magnetic field. This magnetic sensor may be a geomagnetic sensor that detects the geomagnetic field as the target magnetic field.

[0146] The MR element 50 may be formed of the buffer layer 51, the free layer 54, the gap layer 53, the magnetization-resistant layer 52, and the cap layer 55, which are stacked in this order from the lower electrode side 61.

[0147] As described above, a magnetic sensor according to the present invention comprises: at least one magnetoresistive element comprising a plurality of magnetic films stacked on one another; a first ferromagnetic layer made of a ferromagnetic material, the first ferromagnetic layer being deposited so as to overlap the at least one magnetoresistive element when viewed in a first direction orthogonal to a stacking direction of the plurality of magnetic films; an insulator layer made of an insulating material, the insulator layer being deposited on two sides of the at least one magnetoresistive element in a second direction orthogonal to each of the stacking direction and the first direction; and an antiferromagnetic layer deposited on the at least one magnetoresistive element, the first ferromagnetic layer, and the insulator layer.The antiferromagnetic layer has a first antiferromagnetic portion facing the first ferromagnetic layer and a non-facing portion facing the at least one magnetoresistive element and the insulator layer, but not facing the first ferromagnetic layer. There is no magnetic layer between the at least one magnetoresistive element and the antiferromagnetic layer.

[0148] In the magnetic sensor according to the present invention, the first ferromagnetic layer and the first antiferromagnetic part may form a magnetic field generator that generates a magnetic field applied to the at least one magnetoresistive element.

[0149] In the magnetic sensor according to the present invention, the at least one magnetoresistive element may comprise a first magnetoresistive element and a second magnetoresistive element. The first magnetoresistive element and the second magnetoresistive element may be connected in series via the antiferromagnetic layer. The first magnetoresistive element and the second magnetoresistive element may be arranged along the first direction. Alternatively, the first magnetoresistive element and the second magnetoresistive element may be arranged in the second direction.

[0150] The magnetic sensor according to the present invention may further comprise a second ferromagnetic layer formed of a ferromagnetic material, wherein the second ferromagnetic layer is deposited at a position where the at least one magnetoresistive element is disposed between the second ferromagnetic layer and the first ferromagnetic layer in the first direction. The antiferromagnetic layer may further comprise a second antiferromagnetic portion opposite the second ferromagnetic layer. The first ferromagnetic layer and the first antiferromagnetic portion may form a first magnetic field generator that generates a first magnetic field applied to the at least one magnetoresistive element.The second ferromagnetic layer and the second antiferromagnetic part can form a second magnetic field generator that generates a second magnetic field applied to the at least one magnetoresistive element. The at least one magnetoresistive element can comprise a first magnetoresistive element and a second magnetoresistive element. The first magnetoresistive element and the second magnetoresistive element can be connected in parallel in a circuit configuration.

[0151] In the magnetic sensor according to the present invention, the antiferromagnetic layer may be in contact with the at least one magnetoresistive element. The at least one magnetoresistive element may further comprise a non-magnetic metal layer disposed between the antiferromagnetic layer and the plurality of magnetic films and in contact with the antiferromagnetic layer.

[0152] In the magnetic sensor according to the invention, the plurality of magnetic films may include a free layer with a magnetization whose direction is variable depending on a target magnetic field. The first ferromagnetic layer may have a side surface facing the at least one magnetoresistive element. The side surface may include an inclined portion facing the free layer, the inclined portion being inclined with respect to the stacking direction. The angle formed by the inclined portion with respect to the stacking direction may be in a range equal to or greater than 20° and equal to or less than 90°.

[0153] In the magnetic sensor according to the present invention, the at least one magnetoresistive element may have a first surface facing the non-facing part and a second surface opposite the first surface. The distance between at least a part of the non-facing part and the second surface may be the same as the distance between the first surface and the second surface.

[0154] The magnetic sensor according to the present invention may further comprise two yokes deposited on two sides of the at least one magnetoresistive element in the second direction, each of the two yokes being formed of a soft magnetic material. The antiferromagnetic layer may be deposited on the at least one magnetoresistive element, the first ferromagnetic layer, the insulator layer, and the two yokes.

[0155] The magnetic sensor according to the present invention may further include a first terminal, a second terminal, a third terminal, a first resistance portion disposed between the first terminal and the second terminal in a circuit configuration, and a second resistance portion disposed between the second terminal and the third terminal in a circuit configuration. Each of the first resistance portions and the second resistance portion may include the at least one magnetoresistive element, the first ferromagnetic layer, the insulator layer, and the antiferromagnetic layer. The plurality of magnetic films may include a free layer having a magnetization whose direction is variable depending on a target magnetic field.In the first resistance section, the first ferromagnetic layer and the first antiferromagnetic part can form a first magnetic field generator that generates a first magnetic field that is applied to the at least one magnetoresistive element. In the second resistance section, the first ferromagnetic layer and the first antiferromagnetic part can form a second magnetic field generator that generates a second magnetic field that is applied to the at least one magnetoresistive element. The first magnetic field can have, as a main component, a component in a first magnetic field direction that is a direction parallel to the first direction. The second magnetic field can have, as a main component, a component in a second magnetic field direction that is opposite to the first magnetic field direction.In the first resistance section, the magnetization of the free layer can have a component in the first magnetic field direction when the magnetic sensor is not exposed to the target magnetic field. In the second resistance section, the magnetization of the free layer can have a component in the second magnetic field direction when the magnetic sensor is not exposed to the target magnetic field. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2015-125020

[0004] JP 2016-176911

[0004]

Claims

[1] Magnetic sensor (1), comprising: at least one magnetoresistive element (50) comprising a plurality of magnetic films stacked on one another; a first ferromagnetic layer (72) formed of a ferromagnetic material, the first ferromagnetic layer (72) being deposited to overlap the at least one magnetoresistive element (50) when viewed in a first direction orthogonal to a stacking direction of the plurality of magnetic films; an insulator layer (32) formed of an insulating material, wherein the insulator layer (32) is applied to two sides of the at least one magnetoresistive element (50) in a second direction orthogonal to each of the stacking direction and the first direction; and an antiferromagnetic layer (74) deposited on the at least one magnetoresistive element (50), the first ferromagnetic layer (72) and the insulator layer (32), wherein the antiferromagnetic layer (74) has a first antiferromagnetic part (74a) facing the first ferromagnetic layer (72) and a non-facing part (74b) facing the at least one magnetoresistive element (50) and the insulator layer (32) but not facing the first ferromagnetic layer (72), and no magnetic layer is present between the at least one magnetoresistive element (50) and the antiferromagnetic layer (74). [2] Magnetic sensor (1) according to claim 1, wherein the first ferromagnetic layer (72) and the first antiferromagnetic part (74a) form a magnetic field generator (70) that generates a magnetic field that is applied to the at least one magnetoresistive element (50). [3] Magnetic sensor (1) according to claim 1, wherein the at least one magnetoresistive element (50) comprises a first magnetoresistive element (50) and a second magnetoresistive element (50) and the first magnetoresistive element (50) and the second magnetoresistive element (50) are connected in series via the antiferromagnetic layer (74). [4] The magnetic sensor (1) according to claim 3, wherein the first magnetoresistive element (50) and the second magnetoresistive element (50) are arranged along the first direction. [5] The magnetic sensor (1) according to claim 3, wherein the first magnetoresistive element (50) and the second magnetoresistive element (50) are arranged along the second direction. [6] Magnetic sensor (1) according to claim 1, further comprising a second ferromagnetic layer (72) formed from a ferromagnetic material, wherein the second ferromagnetic layer (72) is applied at a position at which the at least one magnetoresistive element (50) is arranged between the second ferromagnetic layer (72) and the first ferromagnetic layer (72) in the first direction, wherein the antiferromagnetic layer (74) further comprises a second antiferromagnetic part (74a) opposite the second ferromagnetic layer (72), the first ferromagnetic layer (72) and the first antiferromagnetic part (74a) form a first magnetic field generator (70) which generates a first magnetic field which is applied to the at least one magnetoresistive element (50), and the second ferromagnetic layer (72) and the second antiferromagnetic part (74a) form a second magnetic field generator (70) which generates a second magnetic field which is applied to the at least one magnetoresistive element (50). [7] Magnetic sensor (1) according to claim 6, wherein the at least one magnetoresistive element (50) comprises a first magnetoresistive element (50) and a second magnetoresistive element (50) and the first magnetoresistive element (50) and the second magnetoresistive element (50) are connected in parallel in a circuit configuration. [8] Magnetic sensor (1) according to claim 1, wherein the antiferromagnetic layer (74) is in contact with the at least one magnetoresistive element (50). [9] The magnetic sensor (1) according to claim 8, wherein the at least one magnetoresistive element (50) further comprises a non-magnetic metal layer (55) disposed between the antiferromagnetic layer (74) and the plurality of magnetic films and in contact with the antiferromagnetic layer (74). [10] Magnetic sensor (1) according to claim 1, wherein the plurality of magnetic films has a free layer (54) with a magnetization whose direction is variable depending on a target magnetic field, the first ferromagnetic layer (72) has a side surface (72a) facing the at least one magnetoresistive element (50), the side surface (72a) has an inclined part (721) opposite the free layer (54), the inclined part (721) being inclined with respect to the stacking direction, and an angle formed by the inclined part (721) with respect to the stacking direction is in a range equal to or greater than 20° and equal to or less than 90°. [11] Magnetic sensor (1) according to claim 1, wherein the at least one magnetoresistive element (50) has a first surface (50a) facing the non-facing part (74b) and a second surface (50b) opposite the first surface (50a), and a distance between at least a portion of the non-facing portion (74b) and the second surface (50b) is the same as a distance between the first surface (50a) and the second surface (50b). [12] Magnetic sensor (1) according to claim 1, further comprising: two yokes (90) applied to two sides of the at least one magnetoresistive element (50) in the second direction, each of the two yokes (90) being formed from a soft magnetic material, wherein the antiferromagnetic layer (74) is applied to the at least one magnetoresistive element (50), the first ferromagnetic layer (72), the insulator layer (32) and the two yokes (90). [13] Magnetic sensor (1) according to claim 1, further comprising: a first terminal (V1, V2, V3); a second connection (E11, E12, E21, E22, E31, E32); a third connection (G1, G2, G3); a first resistance section (R11, R14, R21, R24, R31, R34) applied in a circuit configuration between the first terminal (V1, V2, V3) and the second terminal (E11, E12, E21, E22, E31, E32); and a second resistance section (R12, R13, R22, R23, R32, R33) which is applied in a circuit configuration between the second terminal (E11, E12, E21, E22, E31, E32) and the third terminal (G1, G2, G3), wherein each of the first resistance section (R11, R14, R21, R24, R31, R34) and the second resistance section (R12, R13, R22, R23, R32, R33) comprises the at least one magnetoresistive element (50), the first ferromagnetic layer (72), the insulator layer (32) and the antiferromagnetic layer (74), the plurality of magnetic films has a free layer (54) with a magnetization whose direction is variable depending on a target magnetic field, in the first resistance section (R11, R14, R21, R24, R31, R34), the first ferromagnetic layer (72) and the first antiferromagnetic part (74a) form a first magnetic field generator (70) which generates a first magnetic field which is applied to the at least one magnetoresistive element (50), in the second resistance section (R12, R13, R22, R23, R32, R33), the first ferromagnetic layer (72) and the first antiferromagnetic part (74a) form a second magnetic field generator (70) which generates a second magnetic field which is applied to the at least one magnetoresistive element (50), the first magnetic field has as a main component a component in a first magnetic field direction which is a direction parallel to the first direction, the second magnetic field has as a main component a component in a second magnetic field direction which is opposite to the first magnetic field direction, in the first resistance section (R11, R14, R21, R24, R31, R34), the magnetization of the free layer (54) has a component in the first magnetic field direction when the target magnetic field is not applied to the magnetic sensor (1), and in the second resistance section (R12, R13, R22, R23, R32, R33) the magnetization of the free layer (54) has a component in the second magnetic field direction when the target magnetic field is not applied to the magnetic sensor (1).

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